Sprinting Improves Lactic Threshold

Working at or near maximal intensities isn’t just good for cardiovascular fitness. “Performance in distance events is often determined by what percentage of VO2 max a person can sustain for longer periods of time,” says Joe Di Stefano, a certified strength and conditioning specialist and the Head of Training & Sport for Spartan Race. “This is termed lactic threshold. Varied sprint training improves lactic threshold by allowing an athlete to train at or above their current fitness level, exposing their body to more lactic acid than they’re going to face in the long-distance competition.”

It all gets fairly complicated, but that burning sensation that builds up in your muscles when you push yourself to your limits is the feeling of lactic acid accumulating in your working tissue. Lactic acid accumulates when your body’s ability to use oxygen as a fuel source can’t keep up with its demands. As Di Stefano explains, forcing your body to work at these upper limits kickstarts physiological adaptations that ultimately enhance performance and make you more efficient at using oxygen for fuel, enabling you to sustain higher speeds for longer periods of time.